This minipaper offers a formula which is dual to that of Viskov [5]. While Viskov`s can be thought of as a rising formula for Laguerre polynomials, ours is precisely the lowering one. Besides documenting the formula, which seems to be missing, we want to provide a (rather elementary) operator theory argument instead of making crude calculations. In other words, the annihilation and creation operators are confronted with lowering and rising formulae; they are often failed to be distinguished.